A typical Mobile Radio Data Terminal for vehicular installation has an internal signal processing unit, a radio transmitter and receiver, as well as a display screen, and an externally accessible keyboard. The terminal is designed to communicate with an associated host computer over a designated radio channel. When a message is received, it is conventionally displayed on the screen for user dissemination. Concurrently, if a message is initiated at the Mobile Data Terminal, it is likewise displayed on the screen prior to transmission thereof.
It will be readily appreciated that an incoming message which is placed on the display screen may well distract a user/driver while the vehicle is in motion. Similarly, an obvious hazard is evident should the driver/user of the vehicle attempt to input a message by keyboard while the vehicle is moving. Yet, rendering the Mobile Data Terminal incapable of processing a message during vehicular motion will simply deny communication in its entirety, an obvious undesirable condition.
Accordingly, what is needed is an arrangement that disables both the display screen and keyboard input during those times the associated vehicle is in motion, yet provides some indication to the driver when a message has in fact been received and at least some information as to the nature of such received, but undisplayed message.